The present invention relates to ostomy appliances and particularly those devices used by ostomy patients having an integral or unitized thin barrier gasket formed of a composition which has unique and desirable properties, i.e., breathability, tack, resistance to leakage, dissolution, and disintegration by fluids and cohesive strength. More particularly, the invention relates to the combination of a specific gasket material which may be formed as a composite panel with a hydrophobic backing, as for example, a thermoplastic and which is adapted for integral manufacture onto a conventional ostomy appliance such as a colostomy bag or an ileostomy bag.
The present application is a continuation in part of our earlier application, Ser. No. 398,913, filed July 16, 1982, now U.S. Pat. No. 4,497,914 entitled BREATHABLE OSTOMY GASKET COMPOSITION.
The present invention represents major improvements over existing ostomy appliances especially by virtue of the unique combination of properties afforded by the unitized ostomy appliance and a skin barrier. Utilizing the present invention, high levels of conformability, strength and dry and wet adhesion simultaneously and continuously serve to overcome irregularities in the dynamic peristomal region and serve to provide resistance to the leakage of fluids which result in additional comfort to the wearer since there are no flanges or rings as common with many prior art ostomy appliances to interfere with body movements and to present an objectionable appearance beneath clothing.
Ostomy appliance gaskets based upon the inclusion of Karaya powder, as disclosed in U.S. Pat. No. 3,302,647, are currently in general use. Karaya has certain disadvantages since it is a nutrient substance and capable of supporting the growth of micro-organisms, not only in use, but when contaminated in storage prior to use. Karaya compositions are lacking in cohesiveness, and therefore tend to disintegrate as well as become slippery when wet, often times necessitating the use of a special adhesive to prevent dislocation from the ostomy site.
In U.S. Pat. 4,160,076, there are disclosed hydrophilic foams prepared from a capped polyoxyalkylene polyol reactant having a defined average reaction functionality greater than 2, an aqueous reactant and a carefully balanced combination of a nonionic surface-active agent and a liquid defoaming agent. The resultant foams are characterized by a majority of large size cells and membranes which themselves are formed with small cells. In addition, large amounts of many water-soluble or water-dispersable materials such as cellulosic pigments, dyes, enzymes or the like may be added to the aqueous reactant. By homogeneously distributing these materials in the aqueous reactant they may be distributed throughout the finally prepared foam. However, the large cell size and membranes characteristic of the hydrophilic polyurethane sponges do not possess the necessary properties of tack, elasticity, sealability and flexibility needed in an ostomy gasket.
An ostomy gasket possessing varying degrees of tackiness, lubricity, and softness is disclosed in U.S. Pat. No. 3,980,084. The polymeric ostomy sealing gasket therein disclosed is formed by the polymerization of a hydroxyalkyl acrylate or methacrylate in the presence of a polyalkylene glycol, reducing agent, or chain terminator, and water. In manufacturing the gaskets, it is essential that the polymerization reaction be carried out in the presence of water. In this manner, a considerable quantity of water is absorbed into the polymer matrix during the polymerization reaction. In addition, natural or synthetic gums or cellulosic type materials to increase absorptive capacity may be incorporated into the polymer matrix. However, the material disclosed has a very low elongation at break and will not return to its original shape after deformation. In addition the materials are often highly viscous and therefore lack the sealability preferred for use in an ostomy device which may result in leakage around the ostomy seal.